Electrochemical reaction device

ABSTRACT

In an electrochemical reaction device 10 that electrochemically reduces carbon dioxide, a first power supplying body 27, a first gas flow path structure 24, a cathode 21, a liquid flow path structure 23, an ion exchange membrane 26, an anode 22, a second gas flow path structure 25, and a second power supplying body 28 are laminated in this order, an electrolyte flow path 31 is formed between the cathode 21 and the ion exchange membrane 26, a cathode-side gas flow path 32 for supplying carbon dioxide gas is formed on a side of the cathode 21 opposite to the anode 22, and an anode-side gas flow path 33 is formed on a side of the anode 22 opposite to the anode 21.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an electrochemical reaction device.

Description of Related Art

A technology to obtain valuable resources by electrochemical reduction of exhaust gases and carbon dioxide in the atmosphere is a promising technology that has a possibility of achieving carbon neutrality; its biggest issue is economic efficiency. In order to improve economic efficiency, it is important to reduce loss as much as possible and electrolyze carbon dioxide with high energy efficiency.

Since carbon dioxide electrolysis involves water electrolysis, in addition to the gas flow path for supplying carbon dioxide and discharging gaseous products generated by reduction, the cell that performs carbon dioxide electrolysis needs an electrolyte flow path for supplying and discharging an electrolyte (aqueous solution). Therefore, the cell that performs carbon dioxide electrolysis has a multilayer structure, which is more complicated than the structure of the cell that performs water electrolysis. As an electrochemical reaction device for performing carbon dioxide electrolysis, for example, a device provided with a gas flow path for supplying carbon dioxide gas from a side opposite to a catalyst layer on the gas diffusion layer with respect to a cathode having a catalyst layer formed using a carbon dioxide reduction catalyst on the side of a gas diffusion layer which is in contact with the electrolyte has been disclosed (for example, Patent Document 1).

PATENT DOCUMENTS

[Patent Document 1] PCT International Publication No. 2018/232515

SUMMARY OF THE INVENTION

The energy efficiency of an electrochemical reaction device in the related art as in Patent Document 1 is still insufficient, and it can be said that it would be significant to further reduce the loss and improve the energy efficiency.

An object of the present invention is to provide an electrochemical reaction device capable of electrochemically reducing carbon dioxide with high energy efficiency.

The present invention has adopted the following aspects.

(1) According to an aspect of the present invention, there is provided an electrochemical reaction device (for example, an electrochemical reaction device 10 of the embodiment) that electrochemically reduces carbon dioxide, including: a cathode (for example, a cathode 21 of the embodiment); an anode (for example, an anode 22 of the embodiment); an ion exchange membrane (for example, an ion exchange membrane 26 of the embodiment) adjacent to a surface of the anode on the cathode side; a liquid flow path structure (for example, a liquid flow path structure 23 of the embodiment) which is provided between the cathode and the ion exchange membrane and forms an electrolyte flow path (for example, an electrolyte flow path 31 of the embodiment); a first gas flow path structure (for example, a first gas flow path structure 24 of the embodiment) which is provided on a side of the cathode opposite to the anode, and forms a cathode-side gas flow path (for example, a cathode-side gas flow path 32 of the embodiment) for supplying carbon dioxide gas; a second gas flow path structure (for example, a second gas flow path structure 25 of the embodiment) which is provided on a side of the anode opposite to the cathode, and forms an anode-side gas flow path (for example, an anode-side gas flow path 33 of the embodiment); a first power supplying body (for example, a first power supplying body 27 of the embodiment) provided on a side of the first gas flow path structure opposite to the cathode; and a second power supplying body (for example, a second power supplying body 28 of the embodiment) provided on a side of the second gas flow path structure opposite to the anode.

(2) A plurality of the electrolyte flow paths, the cathode-side gas flow paths, and the anode-side gas flow paths may be respectively formed, and between at least one set of the electrolyte flow paths, the cathode, the anode, and the ion exchange membrane may be sandwiched by a part other than the flow path of the liquid flow path structure, the first gas flow path structure, and the second gas flow path structure.

(3) The number of the cathode-side gas flow paths, the electrolyte liquid flow paths, and the anode-side gas flow paths may be the same, the cathode-side gas flow paths, the electrolyte liquid flow paths, and the anode-side gas flow paths may be arranged so as to overlap each other when viewed from a thickness direction, and between all the adjacent electrolyte flow paths, the cathode, the anode, and the ion exchange membrane may be sandwiched by a part other than the flow path of the liquid flow path structure, the first gas flow path structure, and the second gas flow path structure.

According to the aspects (1) to (3), it is possible to provide an electrochemical reaction device capable of electrochemically reducing carbon dioxide with high energy efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view in which an electrochemical reaction device according to an embodiment is cut along a surface perpendicular to a length direction of an electrolyte flow path.

FIG. 2 is a sectional view in which an electrochemical reaction device of FIG. 1 is cut along a surface in a length direction of an electrolyte flow path.

FIG. 3 is a view when a liquid flow path structure of the electrochemical reaction device of FIG. 1 is viewed from a cathode side.

FIG. 4 is a view when a first gas flow path structure of the electrochemical reaction device of FIG. 1 is viewed from the cathode side.

FIG. 5 is a view when a second gas flow path structure of the electrochemical reaction device of FIG. 1 is viewed from an anode side.

FIG. 6 is a sectional view in which an electrochemical reaction device according to another embodiment is cut along a surface perpendicular to a length direction of an electrolyte flow path.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the dimensions and the like in the drawings provided in the following description are exemplary examples, and the present invention is not necessarily limited thereto, and the present invention can be appropriately changed without changing the gist thereof.

An electrochemical reaction device 10 according to an embodiment illustrated in FIGS. 1 to 5 is a device for electrochemically reducing carbon dioxide. The electrochemical reaction device 10 includes a cathode 21, an anode 22, a liquid flow path structure 23, a first gas flow path structure 24, a second gas flow path structure 25, an ion exchange membrane 26, a first power supplying body 27, and a second power supplying body 28. In the electrochemical reaction device 10, the first power supplying body 27, the first gas flow path structure 24, the cathode 21, the liquid flow path structure 23, the ion exchange membrane 26, the anode 22, the second gas flow path structure 25, and the second power supplying body 28 are laminated in this order.

As illustrated in FIG. 3, six linear slits 23 a are formed parallel to each other in the liquid flow path structure 23. A part of each slit 23 a surrounded by the cathode 21, the ion exchange membrane 26, and the liquid flow path structure 23 is an electrolyte flow path 31. On one side of each electrolyte flow path 31 in the length direction, an inlet-side flow path 31 a for distributing the electrolyte supplied from the outside to each electrolyte flow path 31 is formed. On the other side of each electrolyte flow path 31 in the length direction, an outlet-side flow path 31 b for collecting and discharging the electrolyte flowing through each electrolyte flow path 31 is formed.

The shape of the electrolyte flow path 31 when viewed from the thickness direction is not particularly limited, but a linear shape is preferable because in this case the pressure loss is small.

The height of the electrolyte flow path 31, that is, the distance between both ends of the electrolyte flow path 31 in the thickness direction of the liquid flow path structure 23 may be set to be small within a range where the ion transfer resistance from the cathode 21 to the anode 22 is possible, and can be, for example, 0.1 to 5 mm. The width of the electrolyte flow path 31 can be appropriately set, and can be, for example, 0.1 to 1 mm.

The number of the electrolyte flow paths 31 included in the electrochemical reaction device 10 is not limited to six, can be appropriately set according to the dimensions and the like of the electrochemical reaction device 10, and can be, for example, 5 to 1000 lines.

As illustrated in FIG. 4, six linear grooves 24 a are formed parallel to each other on the surface of the first gas flow path structure 24 on the cathode 21 side. A part of each groove 24 a surrounded by the first gas flow path structure 24 and the cathode 21 is a cathode-side gas flow path 32. On one side of each cathode-side gas flow path 32 in the length direction, an inlet-side flow path 32 a for distributing carbon dioxide gas supplied from the outside to each cathode-side gas flow path 32 is formed. On the other side of each cathode-side gas flow path 32 in the length direction, an outlet-side flow path 32 b for collecting and discharging gaseous products generated by the reduction reaction at the cathode 21 from each cathode-side gas flow path 32 is formed.

In the present embodiment, the inlet-side flow path 31 a of the electrolyte flow path 31 and the inlet-side flow path 32 a of the cathode-side gas flow path 32 are arranged on opposite sides in the length direction of the flow path. In other words, the flow direction of the electrolyte in the electrolyte flow path 31 and the flow direction of the carbon dioxide gas and the gaseous products in the cathode-side gas flow path 32 are opposite directions (countercurrents). From the viewpoint of high carbon dioxide reduction efficiency, an aspect is preferable in which the flow of the electrolyte and the flow of the carbon dioxide gas and the gaseous products are countercurrents as in this example. In addition, the electrochemical reaction device of the embodiment may have an aspect in which the flow direction of the electrolyte and the flow direction of the carbon dioxide gas and the gaseous products are the same direction (parallel flow).

The shape of the cathode-side gas flow path 32 when viewed from the thickness direction may match the shape of the electrolyte flow path 31, but a linear shape is preferable because in this case the pressure loss is small. The dimensions of the cathode-side gas flow path 32 can be set as appropriate. When the cathode-side gas flow path 32 and the electrolyte flow path 31 completely overlap when viewed from the thickness direction, the surface pressure for sandwiching the electrodes can be applied, and from the viewpoint that the electricity supplied from the power supplying body goes evenly to each part without loss, it is preferable that the widths of the cathode-side gas flow path 32 and the electrolyte flow path 31 be the same.

The number of the cathode-side gas flow paths 32 included in the electrochemical reaction device 10 is not limited to six, can be appropriately set according to the dimensions and the like of the electrochemical reaction device 10, and can be, for example, 5 to 1000 lines.

As illustrated in FIG. 5, six linear grooves 25 a are formed parallel to each other on the surface of the second gas flow path structure 25 on the anode 22 side. A part of each groove 25 a surrounded by the second gas flow path structure 25 and the anode 22 is an anode-side gas flow path 33. On one side of each anode-side gas flow path 33 in the length direction, an outlet-side flow path 33 a for collecting and discharging oxygen generated by the anode 22 from each anode-side gas flow path 33 is formed.

The shape of the anode-side gas flow path 33 is not particularly limited, but a linear shape is preferable because in this case the pressure loss is small. The dimensions of the anode-side gas flow path 33 can be set as appropriate. When the anode-side gas flow path 33 and the electrolyte flow path 31 completely overlap when viewed from the thickness direction, the surface pressure for sandwiching the electrodes can be applied, and from the viewpoint that the electricity supplied from the power supplying body goes evenly to each part without loss, it is preferable that the widths of the cathode-side gas flow path 32, the electrolyte flow path 31, and the anode-side gas flow path 33 be the same.

The number of the anode-side gas flow paths 33 included in the electrochemical reaction device 10 is not limited to six, can be appropriately set according to the dimensions and the like of the electrochemical reaction device 10, and can be, for example, 5 to 1000 lines. It is preferable that the number of the electrolyte flow paths 31, the cathode-side gas flow paths 32, and the anode-side gas flow paths 33 be the same.

As described above, in the electrochemical reaction device 10, as illustrated in FIGS. 1 and 2, the plurality of electrolyte flow paths 31 are formed between the cathode 21 and the anode 22, the plurality of cathode-side gas flow paths 32 are formed on the side of the cathode 21 opposite to the anode 22, and the plurality of anode-side gas flow paths 33 are formed on the side of the anode 22 opposite to the cathode 21. In this example, the number of the electrolyte flow paths 31, the cathode-side gas flow paths 32, and the anode-side gas flow paths 33 is the same, and when viewed from the thickness direction (lamination direction), each one of the electrolyte flow paths 31, the cathode-side gas flow paths 32, and the anode-side gas flow paths 33 extends in parallel at the overlapping positions.

The first power supplying body 27 and the second power supplying body 28 are electrically connected to a power supply device (not illustrated). Further, the first gas flow path structure 24 and the second gas flow path structure 25 are conductors, and a voltage can be applied between the cathode 21 and the anode 22 by the power supplied from the power supply device.

The cathode 21 is an electrode for reducing carbon dioxide and water. The cathode 21 may be any electrode as long as the electrode can electrochemically reduce carbon dioxide and the generated gaseous products generated by reduction reaction permeate therethrough to the cathode-side gas flow path 32. Examples thereof include an electrode in which a cathode catalyst layer is formed on the electrolyte flow path 31 side of the gas diffusion layer. A part of the cathode catalyst layer may enter the gas diffusion layer. A porous layer that is denser than the gas diffusion layer may be disposed between the gas diffusion layer and the cathode catalyst layer.

As the cathode catalyst that forms the cathode catalyst layer, a known catalyst that promotes the reduction of carbon dioxide can be used. Specific examples of the cathode catalyst include metals such as gold, silver, copper, platinum, palladium, nickel, cobalt, iron, manganese, titanium, cadmium, zinc, indium, gallium, lead, and tin; alloys and intermetallic compounds of these metals; and metal complexes such as a ruthenium complex and a rhenium complex. Among these, copper and silver are preferable, and copper is more preferable, from the viewpoint that the reduction of carbon dioxide is promoted therewith. As the cathode catalyst, one type may be used alone, or two or more types may be used in combination.

As the cathode catalyst, a supported catalyst in which metal particles are supported on a carbon material (carbon particles, carbon nanotubes, graphene, and the like) may be used.

The gas diffusion layer of the cathode 21 is not particularly limited, and examples thereof include carbon paper and carbon cloth.

The method of producing the cathode 21 is not particularly limited, and examples thereof include a method of applying a liquid composition containing a cathode catalyst to a surface of the gas diffusion layer on the electrolyte flow path 31 side and drying the liquid composition.

The anode 22 is an electrode for oxidizing hydroxide ions to generate oxygen. The anode 22 may be any electrode as long as the electrode can electrochemically oxidize hydroxide ions and the generated oxygen permeates therethrough to the anode-side gas flow path 33. Examples thereof include an electrode in which an anode catalyst layer is formed on the electrolyte flow path 31 side of the gas diffusion layer.

The anode catalyst that forms the anode catalyst layer is not particularly limited, and a known anode catalyst can be used. Specifically, examples thereof include metals such as platinum, palladium, and nickel; alloys and intermetallic compounds of these metals; metal oxides such as manganese oxide, iridium oxide, nickel oxide, cobalt oxide, iron oxide, tin oxide, indium oxide, ruthenium oxide, lithium oxide, and lanthanum oxide; and metal complexes such as a ruthenium complex and a rhenium complex. As the anode catalyst, one type may be used alone, or two or more types may be used in combination.

Examples of the gas diffusion layer of the anode 22 include carbon paper and carbon cloth. Further, as the gas diffusion layer, a porous body such as a mesh material, a punching material, a porous material, or a metal fiber sintered body may be used. Examples of the material of the porous body include metals such as titanium, nickel, and iron, and alloys (for example, SUS) of these metals.

As the ion exchange membrane 26, a known anion exchange membrane may be used as long as hydroxide ions permeate therethrough and oxygen generated at the anode 22 does not permeate therethrough.

Examples of the anion exchange membrane include an anion exchange membrane containing a hydrocarbon-based anion exchange resin. Examples of the hydrocarbon-based anion exchange resin include an anion exchange resin in which various functional groups are introduced into polysulfone, polyetherketone, polyetherether ketone or the like, if necessary.

The thickness of the ion exchange membrane 26 is preferably 0.03 to 0.5 mm, and more preferably 0.05 to 0.1 mm. When the thickness of the ion exchange membrane 26 is the lower limit value or more within the above-described range, mechanical strength and durability can be obtained. When the thickness of the ion exchange membrane 26 is the upper limit value or less within the above-described range, the ion transfer resistance can be suppressed to be low.

Examples of the material of the liquid flow path structure 23 include a fluorocarbon resin such as polytetrafluoroethylene.

Examples of the materials of the first gas flow path structure 24 and the second gas flow path structure 25 include metals such as titanium and SUS; and carbon. Examples of the material of the first power supplying body 27 and the second power supplying body 28 include metals such as copper, gold, titanium, and SUS; and carbon. For the first power supplying body 27 and the second power supplying body 28, those having a surface of a copper base material plated with gold or the like may be used.

When carbon dioxide is electrochemically reduced using the electrochemical reaction device 10, for example, carbon dioxide in the atmosphere or exhaust gas is concentrated by a known concentrating device such as a membrane separation device, and the concentrated gas is absorbed and captured in the absorption liquid such as ethanolamine. Then, the absorption liquid that has absorbed carbon dioxide is heated to release carbon dioxide gas, and the carbon dioxide gas is supplied to the cathode-side gas flow path 32 of the electrochemical reaction device 10. Further, the electrolyte flows through the electrolyte flow path 31 to apply a voltage between the cathode 21 and the anode 22. Accordingly, carbon dioxide is electrochemically reduced at the cathode 21 by carbon dioxide electrolysis accompanied by water electrolysis to obtain gaseous products containing ethylene and the like.

The electrolyte is not particularly limited, and examples thereof include a potassium hydroxide aqueous solution and a sodium hydroxide aqueous solution. Of these, a potassium hydroxide aqueous solution is preferable because the reduction of carbon dioxide is promoted therewith.

At the cathode 21, for example, carbon dioxide is reduced by the following reaction to generate carbon monoxide and ethylene. Hydrogen is also generated at the cathode 21 by the following reaction. The generated gaseous products such as carbon monoxide, ethylene, and hydrogen permeate the gas diffusion layer of the cathode 21 and flow out from the cathode-side gas flow path 32.

CO₂+H₂O→CO+2OH⁻

2CO+8H₂O→C₂H₄+8OH⁻+2H₂O

2H₂O H₂+2OH⁻

Further, the hydroxide ions generated at the cathode 21 move to the anode 22 through the electrolyte and the ion exchange membrane 26, and are oxidized by the following reaction to generate oxygen. The generated oxygen permeates the gas diffusion layer of the anode 22 and is discharged from the anode-side gas flow path 33.

4OH⁻→O₂+2H₂O

In the electrochemical reaction device 10, the ion exchange membrane 26 is provided adjacent to the surface of the anode 22 on the cathode 21 side. In the ion exchange membrane 26, the hydroxide ions move toward the anode 22, but the permeation of oxygen is hindered. Accordingly, the movement of the oxygen generated at the anode 22 to the cathode 21 side is suppressed. Therefore, the loss due to occurrence of the side reaction of oxygen at the cathode 21 is reduced. Further, the ion exchange membrane 26 is provided on the anode 22 side of the electrolyte flow path 31 such that the ion transfer resistance to the anode 22 is reduced. In this manner, the loss in carbon dioxide electrolysis accompanied by water electrolysis is reduced and energy efficiency is increased.

Further, a part of the cathode 21 where the electrolyte flow path 31 and the cathode-side gas flow path 32 exist is not sandwiched between the liquid flow path structure 23 and the second gas flow path structure 25. Therefore, when each of the electrolyte flow path 31, the cathode-side gas flow path 32, and the anode-side gas flow path 33 is one wide flow path, the cathode 21 and the anode 22 are supported only at both ends in the width direction. Therefore, when each laminated member of the electrochemical reaction device 10 is fastened with bolts, nuts, or the like, it is difficult to apply sufficient surface pressure to the cathode 21 and the anode 22. As a result, the current densities in the width direction of the flow paths of the cathode 21 and the anode 22 in the width direction tend to be non-uniform, resulting in energy loss.

On the other hand, as illustrated in FIG. 1, in this example, the number of the electrolyte flow paths 31, the cathode-side gas flow paths 32, and the anode-side gas flow paths 33 is the same, and each flow path is linear and has the same width. Further, when viewed from the thickness direction (lamination direction), the electrolyte flow path 31, the cathode-side gas flow path 32, and the anode-side gas flow path 33 are arranged so as to overlap each other. Then, among all the adjacent electrolyte flow paths 31, the cathode 21 is sandwiched by a part other than the electrolyte flow path 31 of the liquid flow path structure 23 and a part other than the cathode-side gas flow path 32 of the first gas flow path structure 24. Further, among all the adjacent electrolyte flow paths 31, the anode 22 and the ion exchange membrane 26 are sandwiched by a part other than the electrolyte flow path 31 of the liquid flow path structure 23 and a part other than the anode-side gas flow path 33 of the second gas flow path structure 25.

In the electrochemical reaction device 10, with such an aspect, when each laminated member is fastened in the thickness direction (lamination direction) with bolts, nuts, or the like, the surface pressure is firmly applied to the cathode 21, the anode 22, and the ion exchange membrane 26 between adjacent flow paths at multiple points. Accordingly, the first power supplying body 27, the first gas flow path structure 24, and the cathode 21 are in close contact with each other, and thus the loss of electricity supply from the first power supplying body 27 to the cathode 21 can be reduced. Similarly, the second power supplying body 28, the second gas flow path structure 25, and the anode 22 are in close contact with each other, and thus the loss of electricity supply from the second power supplying body 28 to the anode 22 can be reduced. From these facts, in the cathode 21 and the anode 22, the current densities in the width direction of each electrolyte flow path 31 become uniform, and the energy efficiency is further improved.

As described above, in the electrochemical reaction device 10 of the embodiment, the ion exchange membrane 26 is provided adjacent to each other on the cathode 21 side of the anode 22, and the electrolyte flow path 31 is formed between the cathode 21 and the ion exchange membrane 26. Accordingly, the oxygen generated at the anode 22 is prevented from moving to the cathode 21 side by the ion exchange membrane 26, and the loss due to the side reaction of oxygen at the cathode 21 is reduced, and thus high energy efficiency can be realized.

The electrochemical reaction device of the present invention is not limited to the above-described electrochemical reaction device 10. For example, the number of the electrolyte flow paths, the cathode-side gas flow paths, and the anode-side gas flow paths may not be the same as long as the plurality of electrolyte flow paths, cathode-side gas flow paths, and anode-side gas flow paths are formed, and the cathode, the anode, and the ion exchange membrane are sandwiched between at least one set of electrolyte flow paths at a part other than the flow path of the liquid flow path structure and the second gas flow path structure.

Specifically, an electrochemical reaction device 20 illustrated in FIG. 6 may be used. In FIG. 6, the same parts as those in FIG. 1 are given the same reference numerals, and the description thereof will be omitted. The electrochemical reaction device 20 has the same aspect as the electrochemical reaction device 20 except that a liquid flow path structure 23A is provided instead of the liquid flow path structure 23.

In the liquid flow path structure 23A, three wide slits 23 a overlapping both of the two cathode-side gas flow paths 32 adjacent to each other at intervals when viewed from the thickness direction are formed parallel to each other. In addition, parts of each slit 23 a surrounded by the cathode 21, the ion exchange membrane 26, and the liquid flow path structure 23A are three electrolyte flow paths 31A.

In the electrochemical reaction device 20, the electrolyte flow path 31A and the cathode-side gas flow path 32 have a one-to-two correspondence, and when viewed from the thickness direction, two cathode-side gas flow paths 32 are arranged so as to overlap one electrolyte path 31. Similarly, the electrolyte flow path 31A and the anode-side gas flow path 33 have a one-to-two correspondence, and when viewed from the thickness direction, two anode-side gas flow paths 33 are arranged so as to overlap one electrolyte path 31.

Even in the electrochemical reaction device 20, among the adjacent electrolyte flow paths 31A, the cathode 21 is sandwiched by a part other than the electrolyte flow path 31A of the liquid flow path structure 23A and a part other than the cathode-side gas flow path 32 of the first gas flow path structure 24. Similarly, between the adjacent electrolyte flow paths 31A, the anode 22 and the ion exchange membrane 26 are sandwiched by a part other than the electrolyte flow path 31A of the liquid flow path structure 23A and a part other than the anode-side gas flow path 33 of the second gas flow path structure 25.

Therefore, even in the electrochemical reaction device 20, when each laminated member is fastened in the thickness direction (lamination direction) with nuts or the like, the surface pressure is firmly applied to the cathode 21, the anode 22, and the ion exchange membrane 26 between adjacent electrolyte flow paths 31A at multiple points. Therefore, the loss of electricity supply from the first power supplying body 27 to the cathode 21 and electricity supply from the second power supplying body 28 to the anode 22 can be reduced, and the energy efficiency is further improved.

The electrochemical reaction device 10 is preferable to the electrochemical reaction device 20 in that the cathode 21 and the anode 22 can be supported at more multiple points, surface pressure is easily applied to the cathode 21 and the anode 22, and the current density is easily made uniform.

Further, the electrochemical reaction device may be formed with one electrolyte flow path, one cathode-side gas flow path, and one anode-side gas flow path for each as long as the ion exchange membrane is provided adjacent to the cathode side of the anode.

In addition, it is appropriately possible to replace the configuration elements in the above-described embodiment with well-known configuration elements without departing from the spirit of the present invention, and the above-described modification examples may be appropriately combined.

While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary examples of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.

EXPLANATION OF REFERENCES

-   -   10, 20 Electrochemical reaction device     -   21 Cathode     -   22 Anode     -   23, 23A Liquid flow path structure     -   24 First gas flow path structure     -   25 Second gas flow path structure     -   26 Ion Exchange membrane     -   27 First power supplying body     -   28 Second power supplying body     -   31 Electrolyte flow path     -   32 Cathode-side gas flow path     -   33 Anode-side gas flow path 

What is claimed is:
 1. An electrochemical reaction device that electrochemically reduces carbon dioxide, comprising: a cathode; an anode; an ion exchange membrane adjacent to a surface of the anode on the cathode side; a liquid flow path structure which is provided between the cathode and the ion exchange membrane and forms an electrolyte flow path; a first gas flow path structure which is provided on a side of the cathode opposite to the anode, and forms a cathode-side gas flow path for supplying carbon dioxide gas; a second gas flow path structure which is provided on a side of the anode opposite to the cathode, and forms an anode-side gas flow path; a first power supplying body provided on a side of the first gas flow path structure opposite to the cathode; and a second power supplying body provided on a side of the second gas flow path structure opposite to the anode.
 2. The electrochemical reaction device according to claim 1, wherein a plurality of the electrolyte flow paths, the cathode-side gas flow paths, and the anode-side gas flow paths are respectively formed, and between at least one set of the electrolyte flow paths, the cathode, the anode, and the ion exchange membrane are sandwiched by a part other than the flow path of the liquid flow path structure, the first gas flow path structure, and the second gas flow path structure.
 3. The electrochemical reaction device according to claim 2, wherein the number of the cathode-side gas flow paths, the electrolyte liquid flow paths, and the anode-side gas flow paths is the same, the cathode-side gas flow paths, the electrolyte liquid flow paths, and the anode-side gas flow paths are arranged so as to overlap each other when viewed from a thickness direction, and between all the adjacent electrolyte flow paths, the cathode, the anode, and the ion exchange membrane are sandwiched by a part other than the flow path of the liquid flow path structure, the first gas flow path structure, and the second gas flow path structure. 